| The cellular material conserved during routine tests used to identify the origin of stains encountered in forensic testing could be a rich source of DNA. If scientists were able to obtain DNA profiles from extracted serological material, it would improve overall efficiency and reduce the amount of evidentiary stained material consumed during testing. Preliminary forensic serological examinations rely on soluble proteins associated with cellular secretions, such as seminal acid phosphatase (AP) and prostate specific antigen (p30), both present in semen. Historically, the serologist re-solublized a small portion of the stain to extract the soluble proteins and pelleted cellular debris associated with the stain by centrifugation. This research was designed to evaluate DNA yield and DNA typing results from the pelleted cellular debris associated with semen identification methods, as well as correlate serological test results and recovery of complete DNA profiles. Serial dilutions of neat semen deposited on small clippings of material (swatches) were tested for AP, p30, and visually graded based on the number of sperm present. The DNA in the pelleted cellular debris remaining after these tests was organically extracted, quantified, and typed using STR markers. The ability to generate complete DNA profiles from the pelleted material will help scientists to streamline the processing of evidence between stain identification and DNA testing. |
